Caleb TerBush threw two touchdown passes in a near-flawless first half performance, sparking Purdue to an impressive 21-14 upset of No. 21 Illinois on Saturday.

The junior quarterback dissected the Fighting Illini defense over the first 30 minutes, going 12-of-16 for 145 yards with a pair of short scoring passes as the Boilermakers (4-3, 2-1 Big Ten) jumped out to a 21-0 advantage midway through the second quarter.

TerBush finished 16-of-25 for 178 yards as Purdue stayed with the running game for most of the second half.

TerBush, who has rotated with Robert Marve this season, played the entire game and appeared to stake his claim as a full-time starter.

Illinois (6-2, 2-2) was coming off a disappointing 17-7 home loss last weekend against Ohio State and struggled once again to mount consistent offense. The Boilermakers made a conscious effort to limit the amount of big plays A.J. Jenkins – the nation’s second-leading receiver – could create.

Jenkins finished with eight catches for 92 yards, 36 yards less than his season average.

Purdue, which was embarrassed 44-10 in the “Battle for the Cannon” rivalry game last year in Champaign, posted one of its best defensive performances of the year with four sacks. The Boilermakers had six sacks entering the game.

The defense’s bid for a shutout was thwarted midway through the fourth quarter on a 16-yard run by Jason Ford and a late 2-yard sneak by quarterback Nathan Scheelhaase.